A consortium of ten institutions located in North America has been organized, which utilizes the efforts of neuropathologists, pediatric pathologists, a neuroepidemiologist, neurosurgeons, and biostatisticians in a study of childhood brain tumors. Our principal goal is to obtain accurate prognostic information for tumors at specific sites for the design of therapy for individual children, and for studies of competing therapies. The estimated data base from the ten institutions in the comsortium is between 3,000 and 3,400 children. We will use the first surgical sample for the assessment of the prognostic significance of individual histologic patterns and antecedent clinical features. We will use two classifications, that of the World Health Organization, and another one which uses the biologic characteristics of clustering of histologic patterns and life tables. We will choose which of these classifications provides the most accurate prognostic information for tumors at each site within the brain. This information will be entered into the computer via interactive programs which will provide: 1) specific prognostic information for tumors at each of several sites within the brain for individual patient care decisions by any pathologist or neurosurgeon, and 2) prognostic information for the design of studies of competing therapies.